I'd recommend editing another Xtra. Basically the smiley file is a folder. You can open the contents by right-clicking it and choosing "Show Package Contents". Then you can replace the images and edit the definitions in the XML file inside. Play around.

Feel free to use the heart! The whole set is released into the Public Domain so feel free to modify and repackage it in any way you'd like. You don't even have to credit me and you can even sell it (althought that'd be a bit questionable). :) Good luck with your set! ^^

Okay thanks and i credited you. I finished it now, i hope it works though. Would be a pain to fix the problems if any exist. It works on my computer at least. Have to wait for it to get aproved before i can find out XD

Nice little additions to your set too, you might want a broken heart added. Ive seen people use that more than a full heart lol

Since I don't use Mac OS any more I won't be updating this Xtra, but it's fairly simple to do yourself.

Here's how:
1. Use the Download link above to get the .AdiumEmoticonset file
2. Right-click the file and choose Open Package Contents to open it up as a folder
3. Copy any additional image files you want to use as smileys/emoticons into the folder
4. Edit Emoticons.plist with a text editor (TextEdit works fine) and add definitions for the new emoticons. This is basically an XML file, I'm sure you can figure out how to edit it properly.
5. Install your modified version of the package by double-clicking the .AdiumEmoticonset file